Wet wipes and dry wipes and related products have been commonly used by consumers for various cleaning and wiping tasks. For example, many parents have utilized wet wipes to clean the skin of infants and toddlers before and after urination and/or defecation. Many types of wipes both wet and dry are currently commercially available for this purpose.
Today, many consumers are demanding that personal health care products, such as wet wipes, have the ability to not only provide their intended cleaning function, but also to deliver a comfort benefit to the user. In recent studies, it has been shown that baby wet wipes currently on the market are sometimes perceived to be uncomfortably cold upon application to the skin, particularly for newborns. To mitigate this problem, there have been many attempts to produce warming products to warm the wipes to comfort the wet wipe users from the inherent cool sensation given off by the contact of the moistened wipes with the skin.
Warming wipes have been developed utilizing different chemistries, including use of reduction/oxidation reactions or providing crystallization enthalpy of a supersaturated solution capable of imparting a temperature change on the wipes that will provide heat. However, one drawback of utilizing these certain chemistries is the amount needed to warm the wipe.
Additionally, it is known that a sensation of heat is elicited within an individual when the individual touches interlaced warm and cool bars with their skin. The sensations of discomfort and temperature and even pain have been analogized to the burning sensation that accompanies touching extremely cold objects.
One of the prevailing explanations of this warming sensation is that the perception of “heat” is a fusion of sensations resulting from simultaneous activation of warm and cool sensors within the body. Modern physiological findings have confirmed the existence of separate cutaneous receptors for warm and cool. It is interesting to note that the cutaneous receptors that are associated with a cold sensation appear to be activated by low and high temperatures.
A thermal grill is a device that includes interlaced or alternating warm and cool portions that are able to provide a warming sensation to an individual when the individual touches the interlaced warm and cool portions. The relative size, shape, design, configuration, temperature, and orientation of the interlaced warm and cool portions may be varied to adjust the level of discomfort that can be generated within an individual that touches the thermal grill with their skin. However, there is a need to provide a thermal grill that does not provide a feeling of discomfort, but a pleasant feeling of warmth.
Based on the foregoing, there is a need in the art for wipes that can produce a warming sensation just prior to, or at the point of use, without using external heating products by providing the minimum amount of heating chemistries necessary to provide a warming sensation for the entire wipe substrate. It would be desirable if the wipes would produce a warming sensation within less than about 10 seconds after activation and raise the temperature of the wet wipe solution and the wipe substrate at least 5° C. or more for at least 20 seconds.